A. Field of the Invention
FIGS. 1A-G generally illustrate a sports field lighting system (see also the patents incorporated by reference). There is room for improvement with such fixtures and how they are operated.
B. Problems in the Art
The problem of light loss from tilt factor in certain HID lamps is well known. The present applicant has created and patented several ways to operate an arc tube in a glass envelope in a generally horizontal position. See certain of the above-cited patents which are incorporated by reference herein.
There is still room for improvement in this area. Some solutions require structure that must be manually adjusted after the fixture is elevated. This is subject to error and is labor intensive. Some solutions fix the relationship of the arc tube relative the fixture. However, in most sports lighting systems the fixtures vary in angular orientation to the ground. In these cases, it is not possible to insure that all arc tubes for the system end up installed in a horizontal position.
Published Application US 2006/0181880-A1 discloses a method and apparatus for automatic adjustment. However, there remains room for improvement in the art.